Deleting folders with a huge amount of files can be tedious in Windows Explorer: You might end up in watching a progress bar preparing and deleting a lot of files. Even if you don’t want the files to be moved to trash.
If the files should just be deleted, this can be done easier with the command line:
cd foldername DEL /F/Q/S *.* > NUL cd .. RMDIR /Q/S foldername
A lot of explanation / evaluation and even a Context-Menu-Shortcut can be found at this Ghacks article.